：Considering the radial clearance and roller crown profile,the load distribution analysis of cylindrical roller bearings under combined radial forces and bending moments is conducted by utilizing the slice method to solve the three dimensional line contact problem. The time-variable friction forces and moments between the skew roller and inner/outer raceways are then derived based upon the Hertz contact theory and elastohydrodynamic lubrication. By taking the discontinuous contacts between the roller and cage into account,a nonlinear dynamic model is established for analyzing the skidding behavior of skew cylindrical roller bearings under time-variable loads. Through comparisons with both reference and experimental results,the proposed model is verified. From detailed numerical simulations,it is shown that increasing the values of radial load,bending moment or amplitude of time-variable load would all reduces the maximum roller slipping velocity,and attenuates the roller skidding. After considering the time-variable radial load,the frequency of time-varying slipping velocity is not the orbital speed but the combination of the inner race frequency and orbital speed.